Abstract
This study was conducted to evaluate the clinical and radiographic results on titanium stems that were similar in design but differed with regard to proximal grit-blasted surface texture with and without a hydroxy-apatite (HA) coating. We evaluated 40 patients who had undergone primary total hip replacement by a postero-lateral approach. The stems, all made of titanium alloy, tapered, grit-blasted, collarless, with anterior-posterior fins, did present some differences: in a group of 20 stems a proximal hydroxyapatite coating (thickness: 50 μm) was implanted; in another group of 20 stems the proximal surface was without HA coating. Clinical and radiographic evaluations were performed pre-operatively at 3, 6 and 12 mounths during the first year; than once for the following years.The mean duration of follow-up was 6 years.
At the final follow-up examination the Harris hip scores in the HA-coated group (mean, 96 points) and non-HA coated group (mean, 94 points) were similar. Bone-remodelling patterns were similar in the groups and the fast bone integration of the HA coated group. In both groups only two cases of aseptic loosening of the stems were found.
After 6 years of follow-up, the clinical and radiographic results among grit-blasted titanium tapered stems with or without Ha coating were perfectly similar. The optimum final bone integration was due just to the singular shape of femur (type B Dorr’s) with an excellent proximal bone stock. The micromotion of implants reduced the bony-anchored stems in two cases.
